NPS Inventory & Monitoring

The National Park Service Inventory & Monitoring Division (IMD) consists of 32 networks that gather and analyze inventory and monitoring data, and communicate key information on park resources. The monitoring data helps park managers understand how the natural resources are changing over time, enabling them to make science-based management decisions.

Source: Inventory and Monitoring Division (U.S. National Park Service). (n.d.). Retrieved December 13, 2025, from https://www.nps.gov/im/index.htm

Northern Colorado Plateau Network Uplands

The Northern Colorado Plateau Network (NCPN) conducts monitoring for 16 different park units. Upland Vegetation and Soils is considered a high monitoring priority since most of land on the Colorado Plateau is upland ecosystems. Upland areas include rock outcrops, shrublands, grasslands, woodlands, forests, badlands, and subalpine meadows. Plant communities, exotic invasive species, biological soil crusts, soil stability, and hydrologic function are monitored in uplands ecosystems.

Understanding how vegetation cover changes over time helps park managers to detect shifts in plant communities, identify at-risk areas, and make informed management decisions. This analysis quantifies vegetation cover trends at Arches National Park as an example of how upland vegetation monitoring can provide information for resource management and conservation efforts.

Sources: Witwicki D, Thomas H, Weissinger R, Wight A, Topp S, Garman SL, Miller ME. 2017. Upland vegetation and soils monitoring protocol for park units in the Northern Colorado Plateau Network: version 1.07. Natural Resource Report. NPS/NCPN/NRR—2017/1570. National Park Service. Fort Collins, Colorado https://irma.nps.gov/DataStore/Reference/Profile/2248124

Upland Vegetation and Soils (U.S. National Park Service). (n.d.). Retrieved December 13, 2025, from https://www.nps.gov/im/ncpn/uplands.htm

Map of NCPN Park Units
Arches National Park

Arches National Park is located north of Moab in Southeast Utah and is part of NCPN. Elevation in the park ranges from about 4,000 feet in the canyons to 5,200 feet on the rims. With an arid climate, the summers are hot and dry, and the winters are cool to cold. Average annual precipitation is about 8 inches, and temperatures can reach extremes, from -16F to 112F. Most of the park is covered by exposed bedrock, weakly developed soils, and sand dunes. The most common vegetation type in the park is desert shurblands, but woodlands and sparse woodlands are also common.

Sources: Biophysical Description of Arches National Park (U.S. National Park Service). (n.d.). Retrieved December 13, 2025, from https://www.nps.gov/im/ncpn/bpd-arch.htm

Natural resources monitoring at Arches National Park (U.S. National Park Service). (n.d.). Retrieved December 13, 2025, from https://www.nps.gov/im/ncpn/arch.htm

Map of Arches
Sampling Design & Field Methods

Uplands monitoring began in Arches National Park in 2010 to address the management issue of social trailing, and approximately 2,500 hectares are monitored. The sampling unit is a plot and consists of three parallel, 50-meter transects that are spaced 25 meters apart. To increase the overall sample size, a rotating panel design is used where plots are sampled 1-2 years in a row with 3-6 years of rest.

The point-intercept method is used for estimating vegetation and soil surface cover for grassland/shrubland vegetation types. Vegetation and ground cover attributes are recorded at 0.5-meter intervals. A laser is used at each point, and any vegetation, dead or alive, that the laser intercepts is recorded. Additionally, vegetation at any height is recorded.

The Upland Vegetation and Soils Monitoring Protocol, provides in-depth details about the sampling design.

Sources: Hobbs A, Wight A, Livensperger C, Witwicki D, Thomas H, Brehm JR, Miller ME, Weissinger R, Topp S, Garman SL. 2024. Upland Vegetation and Soils Monitoring for the Northern Colorado Plateau Network: 2009-2023 - Data Package. National Park Service. Fort Collins CO https://doi.org/10.57830/2305079

Witwicki D, Thomas H, Weissinger R, Wight A, Topp S, Garman SL, Miller ME. 2017. Upland vegetation and soils monitoring protocol for park units in the Northern Colorado Plateau Network: version 1.07. Natural Resource Report. NPS/NCPN/NRR—2017/1570. National Park Service. Fort Collins, Colorado https://irma.nps.gov/DataStore/Reference/Profile/2248124

Veg Records

1,969

Plots

84

Species

106

Analysis

I downloaded the NCPN point-intercept CSV, read it into R, filtered for only Arches National Park and live vegetation records, then calculated percent cover by species to the plot level.

Since there are 84 plots, I explored the data to find a meaningful way to show vegetation cover change over time for my final product. First, I calculated the maximum change for each species per plot, summed the total change per plot, and reviewed the top five plots with the highest change. Next, I calculated the species change between the first and last survey years and reviewed the plots/species with the greatest change. After this review, I added one additional plot to my list of plots with the highest change.

Without spatial data or knowledge of management actions, I felt the best way to communicate vegetation cover changes was to show park-level species change instead of plot-level. I converted the vegetation cover from percentage to area, summed the cover area by species and year, and then calculated the percent area change in vegetation cover. Since there are 106 different species, I only included the top five species per year for my final graph.

Look at this other stuff!